High-mobility Amorphous InGaZnO Thin-film Transistors with Nitrogen Introduced via Low-temperature Annealing

In this paper, the carrier mobility of amorphous InGaZnO (a-IGZO) thin-film transistor (TFT) was remarkably enhanced by the introduction of nitrogen and the formation of Zn3N2, in which the saturation field-effect mobility (μsat) was 61.6 cm2/Vs. Annealing temperature plays a key role on the enhancement of carrier mobility. When the annealing temperature was increased to 400 °C, μsat was reduced to 4.1 cm2/Vs, which was proposed to be due to the formation of defective ZnxNy based on X-ray photoelectron spectroscopy results. In addition, the a-IGZO TFT with enhanced mobility did not exhibit persistent photoconductivity behavior. The high carrier mobility could expand the application of a-IGZO TFTs to functional circuits in active-matrix displays.